Stable tall oil product



' Patented Nov. 23, 1943 STABLE TALL on. raonncr Torsten Hasselstrom,Savannah, Ga.

No Drawing.

Application December 11, I939,

Serial No. 308,575

(or zen-'97s) 9 Claims.

The present invention relates to sulfate black liquor tall oil, and,more particularly, to stable "sulfate black liquor tall oil, to stablesolid tall oil .rosin and to a process of producing the aforesaid stabletall oil products on an industrial scale.

It is well known in the paper and pulp industry that when black liquorfrom the sulfate process is evaporated, a scum, known as tall oil soap,sep- .arates and floats upon the surface of the black liquor. The talloil soap which is skimmed of! the evaporated black liquor is ready fortreatment. The customary procedure is to add dilute sulfuric acid.Following this addition of acid,

the mass separates into two layers, the upper of which contains crudetall oil. Many efforts have been made to use crude tall oil directly incommerce and industry in a practical and satisfactory manner, and toprovide processes of treating the crude tall oil to make. it availablefor satisfactory use in commerce and industry. These prior efforts havebeen unsuccessful for one reason or another and no completelysuccessfuland wholly satisfactory process has been provided for converting crudetall oil into an industrially and commercially useful and satisfactoryproduct,

I have discovered a process of treating sulfate I black liquor or thetall oil soap obtained there,-

from to produce a refined tall oil and a rosin substitute possessingproperties which make it valuable and useful as a commercial andindustrial product. a I

It is an object of the invention to provide a simple, economical andpractical process for carrying out my discovery on an industrial scale.

orated until the tall oil soap separates. The exact specific gravity towhich the black liquor must be evaporated before the tall oil soapseparates depends upon the alkalinity and viscosity of the black liquoras one skilled in the art readily understands. When the black liquorhasbeen evaporated as aforesaid, crude tall oil soap separates and floatson the surface of the evaporated liquor.

- By skimming off the floating scum, crude tall oil soap may beobtained.

The crude tall oil soap is treated with a suitable acid or acidsubstance, such as sulfuric acid a or acid sodium sulfate, to liberatecrude tall oil. In practice dilute sulfuric acid having a concentrationof about 10-20% or an eight normal solution of acid sodium sulfatehasbeen found to give satisfactory results. After the acid has reacted withthe crude tall oil soap and has been permitted to settle, the mixtureseparates into two layers. The crude tall oil is in the upper layer andcan be obtained by separating the upper and lower layers from eachother. For instance, the upper layer can be removed from the lower layerby syphoning or by any other suitable procedure well knownto thoseskilled in the art.

I have found that the-crude tall oil, which is not very useful, can beconverted into a highly useful refined product by removing certainconstituents. These constituents can be removed satisfactorily bypermitting the tall oil to stand for a period of time, say about 2 daysto about 10 days or so at atmospheric temperatures. Among theconstituents, which are practically completely removed, may be mentionedligneous matters and It is another object of the present invention toprovide a means for producing .from sulfate black liquor tall oil a.heat-treated tall oil, the resin acids of which are stable.

It is a further object of the present invention to provide a stablesolid tall oil rosin.

.It is also within the contemplation of the invention to provide aprocess which is capable of being operated by relatively unskilled laborand which iscapable of producing usefuland valuable by-productsincluding crude and refined tall oil rosin.

Other objects parent from the following description of a preferredprocedure for carrying thepresent invention into practice.

vBlack liquor produced in the sulfate process of producing pulp andpaper is used as the raw material and is termedherein sulfate black liq-'uor"'for convenience. The black liquor isevapand advantages will becomeap higher saturated fatty acids. In addition, the

refined product contains reduced amounts of oxidized colophonic acidsand colophonic acids (classified according to Aschan's system) andreduced amounts of non-saponifiable matter than the crude tall oil. Inpractice, the foregoing constituents separate out from the tall .oil onstanding and may be removed by filtering, decanting, or the like. Thefiltrate is refinedtall oil which is relatively stable and which isveryuseful commercially andindustrially. Among the important uses, Ihave discovered for refined tall oil, soap making and .flotation ofcertain ores of the alkaline earth metals may be mentioned. 'I'hialatter'dlsc'overy is described and claimed in applications, Serial No.578,842, flied December 3, 1931- (United States Letters Patent No.1,986,816), and Serial No. 648, 215, filed December 21, 1932 (UnitedStates Letters Patent No. 1,986,817)

In some instances, the refining operation may be carried still further.For instance, by'refrlgall of the prior art source,

- foreninger, Terpener och Kamferarter,

range of about C. to about minus 10 0., say abouto" C. and maintainingit at the refrigerated temperature for a period of say-"a week to tendays base, with or without aeration, it is possible to remove furtherconstituents from the tall oil.

' The solids which have separated from the liquid v I 7 assavss cratingthe tall 011 ata' temperahire within a it was deemed necessary toreinvestigate Aschan's It has also been found that the solids separatedfrom --the liquid tall oil can be melted together to'form a productwhich can be used as a substitute for rosin. The solids may be usedseparately for the aforesaid purpose. if it is desired. It will thus beobserved that the by-products are useful and valuable instead of beinguseless.

Although many attempts have been made to apply the experience obtainedin the treatment of Scandinavian of domestic tall 011. most of theseeflorts have failed. These failures undoubtedly have been at leastpartially due to the fact the Scandinavian tall oil differs fromdomestic tall oil. Furthermore the products produced by these prior artprocesses have not been concisely defined. Many of the prior artproducts and in fact practically products have been mixtures of two ormore materials, which, due to the lack of knowledge of resin acids havenot been defined with such particularity as to readily enable even e pts in the art to recognize the components of these products. It will beappreciated that 'imtil recently the research work done on the resinacidsofrosinandoftalloilhasbeenveryvague because of the difficultiesencountered in the separation of the resin acids in the tall 011 and therecognition of these resin acids as characteristic chemical individuals.

As has been shown by tree is subjected to the alkaline pulping process(sulfate process), the sapietic acidjis converted into Steele's abieticacid which is the terminal resin acid of sulfate tall oil press cake.[Hasselstrom and Bogart, ibid., 2120.] On the other hand when crudesulfate tall 011 from a foreign as for example from Scandinavian pine isdistilled there is isolated from the distillate an acid named by theoriginal discoverers, Aschan and collaborators, pinabietic acid.[Aschan, Finska Kemistsamfundet 1917: Aschan, Naften- Helsingfors, 353(1936).]

In view of the fact that these investigators had not succeeded inobtaining a pinabietic acid of constant melting point and opticalrotation, and in view of the fact that as shown in work done on Americantall oil that Steele's abietic acid was present in American tall oil andnot previously recorded as present in Finnish tall oil,

sulfate tall oil to the treatment I Hasselstrom and Bogert [\T. A. C. 5.572118 (1935) 1, the original resin etic acid it has conditions.Consequently materials such as appear that the acid (CsoHssOa)pinabietic acid to determine more conclusively what its constituentswere. A sample of Aschans pinabietic acid was subjected to fractionalcrystallization substantially according to Aschan -et a1. [Aschan,Naftenforeninger, Terpener och Kamferarter, Helsingfors, 353, (1926)].main fractions were then sulfonated according to Hasselstrom (U. 8.Patent No. 2,121,032). The sulfonation product was identified by itsdimethyl ester as dehydroabietic acid sulfonate, thus proving that thepinabietic acid of Finnish tall oil contained dehydroabietic acid. .Bymeans of the lactone of hydroxy tetra hydroabietic acid it was proventhat Finnish tall oil also contains dihydroabietic acid. I r

The resin acids in the mother liquors of the second fraction wereconverted to the acid sodium salt (CnHaCOONaBC-aHuOQ) according toPalkin and Harris [ibid. 56 1935 (1934)] and then recrystallized toconstant optical rotation. The product thus obtained, the acidregenerated therefrom and the subsequently, prepared di-namylamine saltand the again liberated acid did not differ from theSteele-Palkin-Harris abietic acid and corresponding derivatives of-thesame.

Thus it is evident that Finnish tall oil, in addition to containingdehydroabietic acid also contains Steele's abietic acid.

The last fraction of the pinabietic acid crystallizations, i. e., 0.6%of the original starting material,-was converted into the di-n-amylaminesalt.

This salt and the recovered acid prepared therefrom did not show anyconstancy in melting point or optical rotation. Therefore it wouldhighest melting fraction of pinabietic acid, and, consequently, Finnishtall oil in addition to hydroabietic acid contain small amounts of thedihydroabietic acid described by Ruzicka et al [Ruzicka, Bacon,Sternback and Waldman, Helv.

Chim. Acta. 21, 59 (1938)], Hasselstrom et al. U. S. Patent 2,072,628,and Hasselstrom and McPherson U. A. C. S. 61 1228 (1939) l.

Great variations in optical rotation were observed throughout this workand particularly in the recovered acid fractions from the dim-amylaminesalt of the highest melting fraction of the was due presumably to thepinabietic acid. a This fact that dehydro and tallize together withamounts depending upon the concentrations of solutions used in therecrystallizations and hence can not beseparated by fractionalcrystallization alone. This has been recognized by the experts in theart as reference to Hasselstrom (U. 8. Patent No. 2,072,628)

dihydro abietic acid crys- Fleck and Palkin [ibid., 60, 2621 (1938)]will clearly show.

Asa result of this re-investigation of pinabiacid is not a chemicalindividual but a mixture of dehydroabietic acid (0201-12002)dihydroabietic Steele's abietic acid (CzoHaoOs) and d-pimaric acid.These three types of abietic acid exhibit a varying stability toatmospheric Steele's abietic acid or materials acids-asthose of commonrosin or in the resin acids of tall oil press stable to atmosphericconditions rich in such cake are not or when exposed to' oxygen.However, crude tall oil and tall oil press cake can be converted into astable form by treatment in accordance with the principles of thepresent invention.

Thus, it has been The the Steele's abietic acid and de-' Steele'sabietic acid in.

Fieser and Campbell [J.-A.

become evident that pinabietic materials rich found. that the solidsseparated from the liquid portion of sulfate tall oil can be meltedtogether during a period of about 6 to about 12 hours to form a productwhich may be used as a substitute for rosin. By treatment undercarefully controlled conditions and distillation of the product soobtained, itis possible to obtain a product the resin acids of whichhave a marked stability to the atmosphere and particularly to oxygen.

Broadly stated, my new oxygen stable or stable tall oil products may beproduced by heating 1 the crude sulfate tall oil, refined sulfate talloil and/or press cake obtained as described hereinbefore to temperaturesof about 200-about 300 centigrade and distilling the product under amedium vacuum at temperatures of about,240'- about 260 centigrade. Theproduct so obtained is substantially devoid of Steele's abietic acid,

CaoHaoOa, but does contain dehydroabietic acid CaoHraOz, dihydroabieticacid CaoHsaOz, abietenes, fatty acids, sterols and ligneous matter. Inorder that those skilled in the art may have a better understanding ofthe principles of themesent invention, the following description ofpre-- ferred embodiments thereof is provided.

Press cake obtained as hereinbefore described common wood or gum rosinknown as colophony. In other words. the present invention provides asuperior grade of rosin substitute. Of course the product may be furtherpurified if desirable.

For the p r e of giving those skilled in the art a better understandingof means for carrying the invention into practice, the followingillustrative examples will be given:

is heat treated for from 1 to 24 hours or until the resin acids of theabietic type have substantially undergone a rearrangement ofdisproportiona- -tion of hydrogen andis substantially devoid of Steele'sabietic acid. My novel stable solid tall oil rosin can likewise beobtained by heat treat ing 'crude tall oil or refined tall oil (U. 8.Patent No. 1,986,817) for from 2 to 24 hours to 200 to 300 centigradeand then distilling under a vacuum of about 10 millimeters of mercury.The product obtained as a distillate between the temperatures of'about220 C. to about 280 C. has a positive sign of rotation and provides amixture of fatty acids, sterols, ligneous matter, abietenes,

dehydroabietic acid and is substantially devoid of Steeles abietic acid.The presence of the abietenes probably is due tothe decarboxylation' ofthe Steele's abietic acid originally in the tall My novel product canalso be obtained by distilling sulfate tall oil press cake under amedium vacuum of about 5 to about 100 millimeters of,

mercury and segregating that portion of the distiliate which distillsover at about 240 centigrade say from about 240 centigrade to about 280centigrade. This distillation should be carried out at a rate such thatabout 6 to about 8 hours is required for the distillation of about 5kilos of solids when the distillation is carried out in the usuallaboratory size equipment. Of course it is to be appreciated that withlarger quantities and larger equipment, the time of distillation will bemore or less proportionate. In other words it is essential to submit thecrude material to a heat treatment of about 1 to about 24 hours and thespeed of distillation should be controlled in accordance with thiscritical feature of my invention. i

It was found that a more convenient method for commercial use forisolating the resin acids from the press cake is as follows: The presscake is distilled under a vacuum at about 10 to 80 mm. pressure and at atemperature of about 240 to 280 C. This procedure is carried out for aprolonged period, preferably about 4 to about 10 hours. The distillateobtained from the foregoing operation contains a rosin substitute havinga light color. The rosin substitute which is thus obtained is morestable to light and air than grams.

Exmnn No. 1 7 About 200 grams of solids separated from the refined talloil (sulfate tail oil press cake) is subiected to distillation at 20 mm.pressure and the following fractions are obtained from the distiilate:

1. A fraction up to about 238 0. yields about 48.0 grams of higher fattyacids and decomposition products. a

2. A fraction from about 240 to about 260 0. yields about 143.5 grams ofwater white solid rosin substitute.

3. A residue of pitch amounting to about 20.0

Exlmrn: No. 2

About 700 grams of solids obtained from the refined tall oil as setforth hereinabove and havingan acid number of 176.6 was subjected todistillation for about 6 hours under the following conditions to producethe following fractions:

1. A fraction at a temperature of about 254 C. and under a pressureabout 40 mm. of mercury gives a yield 50 grams of fatty acids with anacid number of 267.4.

2. A fraction at a temperature of about 254 to about 257 C. and under apressure of about 80 mm. of mercury gives a yield of about 100 grams offatty acids with an acid number of 3. A fraction at a temperature ofabout 256 to about 278C. and under a pressure of about 80 mm. of mercurygives a yield of about 280 rams soft rosin substitute with an acidnumber of 143.9. I

4. A residue of pitch remained amounting to about 84- grams and having alow acid number.

' Fraction 2 of Example 1 and Fraction 3 of Example 2 provide my newstable solid sulfate tall oil rosin.

.Exlluru: No. 3

About 1000 grams of crude sulfate tall oil were heated to about 200 toabout 300 centigrade and maintained at that temperature for about 10hours. The heat treated crude sulfate tall oil was then subjected todistillation under a vacuum of about 40 millimeters of mercury and thatportion of the distillate distilling at about 240 to about 280centigrade isolated. This fraction of the distillate is my novel stablesolid tall oil rosin.

Exauru: No. 4

About 100 grams of press cake were subjected to heat treatment at about280 centrigrade for about 3 to about 4 hours. The product thus obtainedis substantially devoid of Steeles-abietic acid and containsdehydroabietic acid and dihydroabietic acid.

g My new stable sulfate tall oil rosin comprises I about 2 to about 35%dehydroabietic acid and about 1 to about 50% of fatty acids, sterols,ligneous matter and abietenes, but is substantially devoid ofSteele'sabietic acid. My new stable solid sulfate tall oil rosin beingrich in dehydroabietic acid is exceedingly stable to oxidation or theaction of the atmosphere. This is readily foregoing patents contain lessthan from methanol and approximately 5 gram samples of the pulverizedcrystals rich in dehydroabietic acid, CroHzaOz, were exposed to astream'of oxygen. The table below gives the p ntage gain in weight per 5 gramsample of each material after exposure to the stream of oxygen for theindicated period of time.

/ Stability test (Percentage gain of approximately 5 gram samples inoxygen stream) Pure Tali oil Steele's Pin deh dro- Hours 0 wh algistllcab etlic 9 3 ga t l H; ac

' I QN M f Percent Percent Percent Percent Percent 0. 564 0. 162 0. 0000. 292 0. oao 0. 823 0. 116 0. 018 0. 080 0. 014 0. 978 0. 156 0. 008 0.178 -0. 000 1. 070 0. 112 0. 004 0. 148 -0. 002 0. 892 0. 134 +0. 006 0.154 0. 004 0. 876 0. 130 0. 000 0. 156 0. 000 0. 760 0. 134 0. 002 0.232 0. 004

from the undersirable solid constituents mentioned hereinabove may beemployed, such as vacuum distillation with or without the use of steam.Furthermore, filter aids, such as kieselguhr, silo-cel, diatomaceousearth, and the like, may be employed to facilitate filtration orseparation of the undesired solid constituents.

Those skilled in the art will appreciate that my novel stable solidsulfate tall oil rosin is far more stable than Steele's abietic acid,pinabietic acid or gum rosin and has a stability at least equal to puredehydroabietic acid. My new product, to wit: the new stable solidsulfate tall oil rosin provides a superior product for incorporation insoaps, lubrication greases, etc. I

Although the present invention has been described in conjunction withcertain preferred embodiments it is to be understood that variations andmodifications thereof may be made as those skilled in the art willreadily understand. Such variations and modifications I consider to bewithin the purview of the specification and the scope of the appendedclaims. Thus it is to be understood that the term "heat treated" asemployed in the appended claims defines a material derived from crudesulfate tall oil which has been treated until the resin acids of theabietic type have'substantially undergone rear:

rangement or disproportionation of hydrogen. For example, solid crude.tall'oil resin contains the resin acid having an elemental formula approximately CzoI-koOz and having a negative sign of optical rotation,whereas heat treated solid crude'tall oil resin contains a resin acidhaving a positive sign of optical rotation. Furthermore, solid crudesulfate tall 011 resin contains Steeles abietic acid whereas heattreated solid crude sulfate tall 011 resin is substantially devoid ofSteele's abietic acid. It is likewise to be observed that my new stablesulfate tall oil products are not to be confused with the products ofthe processes disclosed in U. B. Patents Nos. 1,593,656, 1,810,472,1,997,171, 1,940,372, 1,826,224, 1,921,566, 1,888,581 and 2,012,125,since all the products of the processes described in the foregoingpatents contain Steele's abietic acid and are practically devoid ofdehydroabietic acid. That is to say, the products produced by theprocesses described in the about 2% of Similarly, the heat treatasdescribed in U. B.

'dehydroabietic acid. ment of wood rosin Patent heattre 4 hours, wherebysulfate tall It is to be noted that the raw material or crude tall oilsoap is obtained from black liquor of the sulfate process of paper orpulp making. This pulping process is well known to chemists and is notto be confused with the sulfite process or other processes. The liquorobtained from these processes would not yield my stable tall 011products.

The present application is a continuation in part of my co-pendingapplication, Serial No. 845, filed on January 8, 1935, which maturedinto U. S. Patent I claim:

1. A process for producing sulfate tall oil and sulfate tall oilproducts stabilized to oxygen-containing gases which comprises heatingat least one of the group consisting of crude sulfate tall oil, refinedsulfate tall oil and the solids separated from crude sulfate tall oilafter said crude sulfate tall oil stands at atmospheric temperatures fora period of time of about 2 days to about 10 days, said heating beingcarried out between about 200 C. and about 300 C. for about 1 to about24 hours, whereby the resinic portions of the heat treated materialunstable to oxygen-containing gases are converted to oxygen-stable and aproduct is produced .which is substantially devoid of Steele's abieticacid and contains dehydroabietic acid in amounts of about 2% to about35% of the resinic portion of the heat treated material. 7 I,

2. A process for producing a sulfate tall 01] derivative stable to airwhich comprises subjecting crude sulfate tall oil to a temperature ofabout 200 to about 300 C. for about 10 hours to obtain heat treatedsulfate tall oil, subjecting said heat treated sulfate tail on todistillation under a vacuum of about 40 millimeters of mercury andobtained being substantially devoid of Steele's more than about 2%abietic acid and containing of dehydroabietic acid. 7

3. A process for producing sulfate tall oil rosin substantially devoidof comprises heating solids separated from crude sulfate tall .011 aftercooling and settling at a temperature of about 280 C. for about 3 toabout substantially devoid of Steele's abietic acid and containingdihydroabietic acid and more than about 2% of dehydroabietlc acid.

4. As a new treated sulphate group consisting tall oil.

tall oil product selected from the of heat treated crude sulphate heattreated refined sulphate tall 011,

talloilreslnandted solid crude sulphate No. 2,190,660 on February 20,1940.

substances.

Steele's, abietic acid which 011 rosin is obtained article ofmanufacture, a heat assures mixtures of the aforesaid, said heat treatedsulphate tall 011 product being substantially devoid of Steelesabieticacid, but characterized by an increase in weight of not more thanabout 0.004% when grams of said product recrystallized from methanol areexposed to the action of a stream of oxygen for about 120 hours and theresinic portion of said heat treated sulphate tall oil productcontaining about 2% to about 35% dehydroabietlc hydroabietic acid anddehydroabietic acid and being substantially devoid of Steeles abieticacid; the dehydroabietic acid being present in amounts of about 2% toabout 35% of the resinic portion of said fraction. v

' '7. As a new article of manufacture, heat treated solid crude sulphatetall 011 resin, said heat treated solid crude sulphate tall oil resinbeing substantially devoid of Steeles abietic acid and the resinicportion of said heat treated solid crude sulphate tall oi1 resincontaining about 2% to about dehydroabietic acid.

8. As a new article of manufacture, a fraction of heat treated solidcrude sulphate tall 011 resin having a distillation range of about 240C. to about 280 C. at a pressure of about 5 to milli meters of mercury,being substantially devoid of Steeles abietic acid and containingstero1s,ligneous matter, abietenes and dehydroabietic acid.

9. As a new article of manufacture, a fraction of heat treated solidcrude sulphate tall oil resin having a distillation range of about 220C. to about 280 C. at 10 millimeters of mercury, having a positive signof optical rotation and comprising fatty acids, sterols. ligneousmatter, abietenes, dehydroabietic acid and being substantially devoid ofSteeles abietic acid.

TORS'IEN HASSELSTROML

